生态恢复背景下关中地区城镇与植被空间优化协调研究

针对关中地区城市化土地利用与生态建设的关系,利用2000年和2008年的TM、ETM+与MODIS影像,在不同尺度的格网下,基于土地利用度、生态位理论、廊道与点轴理论,并采用对山脊线山谷线提取的方法,从格局、过程和机理等角度进行研究,实现区域格局优化,并进行功能分区。研究结论如下:①研究区2000—2008年东部与中部土地利用程度增加、西部与南北部分土地利用程度下降,而LAI整体上增加显著,城市发展与植被恢复相对协调;②基于空间生态位理论,绝大多数区县的现实生态位都超过基础生态位的50%,表明调控可从区县所辖乡镇进行,并按照现实生态位范围进行城市发展阻力测算;③选用基于DEM的山脊线山谷线提取方法,获得关中地区景观生态廊道、城市发展轴线和缓冲区,并据此将研究区乡镇分为城市扩展型、双轨并重型、生态建设型。

Study on the Spatial Optimizing and Coordination of Cities and Ground Vegetation Under the Background of Ecological Restoration in Guanzhong Region

The spatial-temporal changes on the land use/cover pattern are the interaction processes influenced by eco-environment and socio-economy. It is necessary to take a comprehensive research to analyze the interaction and mechanism in the process, so that the spatial layout of cities and ground vegetation can be figured out. In view of the relationship of which between the land use in urbanization and the eco-environmental construction is often complex, this study is based on the vegetation changes in different grids that aim to find the optimal partitions of the land resource in the study area. In the analysis, a regional structure optimization is given, and the mechanism perspective has been researched on. By virtue of the theories and methods such as ecological niche, minimum cost distance, point axis development theory, ecological corridor, and so on, the conclusions are drawn as follows: 1) From 2000 to 2007, the land use degree increased in the central and eastern parts of the study area, while dropped in the western, northern and southern parts. And there was a relatively high coordination degree between city development and ecological restoration. Of the total 748 samples, both land use degree and LAI were increased in 393 samples. 2) Based on spatial ecological niche theory, in most cities and counties, the reality niche accounted for more than 50% of the foundation niche. This phenomenon suggested that the contradictions between urbanization and vegetation restoration can be solved at the township level, and the accumulative cost for every city can be calculated based on the reality niche. 3) An extract method for DEM was chosen and the ridge lines and valley lines of urbanization resistance were extracted. And the key parameter of curvature is artificially defined as 3. Based on the concept of point axis development theory and landscape ecological corridors theory, the study area is divided into three types as urban expansion zone, vegetation restoration zone and double track development zone. The discussion mentioned that there are a lot of uncertainties existing in the remote sensing image analysis, so more comprehensive statistical data should be adopted. In this article we innovatively introduced DEM extraction method to analyze the spatial layout of land resource, from which the three zones can be set up by one curvature, hence the subjective uncertainty can be lessened in contrast to the traditional methods. Finally, refering to the spatial scale of land resource researches, we hold that the scale from hundreds meters to several kilometers is suitable.